EFSM的等价转换和通信协议一致性测试

绝大多数通信协议是以ＥＦＳＭ（扩展的有限状态机）来描述的。本文首先给出ＥＦＳＭ的形式化定义，然后提出ＥＦＳＭ的一种等价转换算法及其证明。通过协议转换，可以使生成一致性测试集的方法得到简化，并且生成的测试实例具备一定的诊断数据流错误的能力     

基于形式规范的协议一致性测试的可靠性分析

可以用于形式规范的描述语言很多,但存在一种统一的方法对形式规范进行一致性测试。该文采用统计的方法分析基于形式规范的协议一致性测试的可靠性,通过计算给出待测实体经过这种测试后所能达到的可靠性的置信区间,特别指出在零错误下影响可靠性的条件。     

计算机病毒入侵检测技术探讨

计算机病毒是一类很常见的信息安全威胁.本文讨论了病毒的工作原理和检测病毒的常用技术.然后提出了一种基于自我复制行为的病毒检测方法，用图灵机模型给出了形式化的描述，并定性地证明了这种方法可以在图灵机的计算能力范围内自动进行.     

基于B方法验证技术的应用研究

形式化B方法建立在严格的数学基础上,通过严格的验证技术证明其正确性,尤其对大型复杂系统的描述是非常有用和正确的。用形式化B方法描述了免疫系统的两个因子网络模型,然后通过严格和精确的验证技术:类型检查和证明义务的给出,证明了抽象机的正确性。     

Efficient test case generation for validation of UML activity diagrams

Unified Modeling Language (UML) is widely used as a system level specification language in embedded system design. Due to the increasing complexity of embedded systems, the analysis and validation of UML specifications is becoming a challenge. UML activity diagram is promising to modeling the overall system behavior. However, lack of techniques for automated test case generation is one major bottleneck in the UML activity diagram validation. This article presents a methodology for automatically generating test cases based on various model checking techniques. It makes three primary contributions: First, we propose coverage-driven mapping rules that can automatically translate activity diagram to formal models. Next, we present a procedure for automatic property generation according to error models. Finally, we apply various model checking based test case generation techniques to enable efficient test case generation. Our experimental results demonstrate that our approach can reduce the validation effort drastically by reducing both test case generation time and required number of test cases to achieve a functional coverage goal.     

Agent结构的形式化描述分析及研究

Agent结构描述存在抽象、复杂和不完整等问题,很难应用于实际Agent的构造。基于物理和设计立场,提出一种新的Agent结构模型,并作了形式化描述。解决了Agent模型与具体Agent结构、行为和目标的映射问题。构造的电子谈判实例验证了它的正确性和有效性。     

CORBA规范的形式化描述及分析

CORBA为构建大规模分布式应用程序提供了一套公共对象服务规范,其规范主要以IDL语言编写,只提供对象的静态行为描述．提出并应用扩展有色Petri网对CORBA对象进行形式化模拟和分析,结果表明扩展有色Pctri网模型不仅能够清楚描述对象的静态行为,同时也能较好地模拟对象分布性和动态行为．     

系统维修中的顺序诊断策略

对复杂系统的维修过程,需要构建一种有效的测试序列作为测试诊断策略,以获得高的故障隔离精度,并使包括测试费用、测试时间、测试所需的人力物力等在内的测试代价较低.针对系统维修中的顺序诊断策略问题,给出了问题的一般描述.对测试排序问题的最优算法,进行了算法过程分析并说明其在实现中存在的问题.在此基础上研究一种次优顺序诊断算法,即基于信息试探(IG)的诊断树产生算法,给出了根据系统相关矩阵进行算法设计的步骤,并将这种算法与最优算法进行了理论和实例仿真比较.结果表明基于信息试探的诊断树产生算法简单、实时性好,可用于复杂系统的在线诊断测试和雏修诊断过程.     

一种面向对象的自主网络管理模型

针对ＳＮＭＰ协议的局限性,将网络管理信息在被管对象和网管对象两个层次上进行抽象;给出了网管对象的语义及自主网管代理Ａｇｅｎｔ的形式化描述;并基于此设计了一种实现高层网管功能的自主网络管理模型。使用这一网管模型,能使网络管理的结构规范、清晰;便于扩充网管功能;并易于实现两个网络系统间的交互和合作。     

基于结构化保护的高安全级系统可信模型

In order to ensure the security of information systems, it's essential to make sure that system behav-iors are trusted. By analyzing threats that exist in execu-ting procedures, a trust model based on structured pro-tection is proposed. We consider that functional compo-nents, system actions and message flows between com-ponents are three key factors of information systems. Structured protection requirements on components, con-nections and action parameters are also provided. Four trusted properties of the model are deducted through formal analysis, and trusted system behavior is defined based on these properties. Furthermore, decision theo-rem of trusted system behavior is proved. The devel-oped prototype system indicates the model is practical. It is a general theory model built on logic deduction and independent on specific environment and the behaviors of the system designed and implemented following the model are trusted.     

Modeling and Interoperability Test Case Generation of a Real-Time QoS Monitoring Protocol

QoS monitoring is a kind of real-time systems which allows each level of the system to track the ongoing QoS levels achieved by the lower network layers. For these systems, real-time communication between corresponding transport protocol objects is essential for their correct behavior. When two or more entities are employed to perform a certain task as in the case of communication protocols, the capability to do so is called interoperability and considered as the essential aspect of correctness of communication systems. This paper describes a formal approach on modeling and interoperability test case generation of a real-time QoS monitoring protocol. For this, we specify the behavior of flow monitoring of transport layer QoS protocol, i.e., METS protocol, which is proposed to address QoS from an end-to-end's point of view, based on QoS architecture model which includes ATM network in lower layers. We use a real-time Input/Output Finite State Machine to model the behavior of real-time flow monitoring over time. From the modeled real-time I/OFSM, we generate interoperability test cases to check the correctness of METS protocol's flow monitoring behaviors for two end systems. A new approach to efficient interoperability testing is described and the method of interoperability test cases generation is shown with the example of METS protocol's flow monitoring. The current TTCN is not appropriate for testing real-time and multimedia systems. Because test events in TTCN are for message-based system and not for stream-based systems, the real-time in TTCN can only be approximated. This paper also proposes the notation of real-time Abstract Test Suite by means of real-time extension of TTCN. This approach gives the advantages that only a few syntactical changes are necessary, and TTCN and real-time TTCN are compatible. This formal approach on interoperability testing can be applied to the real-time protocols related to IMT-2000, B-ISDN and real-time systems.     

Using flows for describing and verifying the behaviour of interactive systems

In some contexts, especially in safety or security critical applications, it may be crucial to verify that the interactive behaviour of these systems possess certain formally expressed properties. Our project is to describe the interactive behaviour of a system by building an abstract formal model of it and to verify automatically that this behaviour possesses the required properties. In this paper, we suggest to use data flows for this purpose. We use the formal language Lustre to denote such flows. This language permits to express safety temporal properties and to build some syntactical structures in order to verify and test them by using appropriate tools.     

一种通信协议测试序列生成的新方法

本文讨论了一种协议测试的新方法,它使用构造类别代数述通信协议规范,然后根据规范中的公理部分生成测试序列。本文以栈规范为例介绍这种方法的应用。并通过与基于有限状态机的测试序列生成方法相比较,得出两种方法在一些方面是等效的,但在处理状态较多的协议时,这种方法有一定的优点。